| Annie Sullivan | 99e2ef3 | 2020-08-11 14:45:42 | [diff] [blame] | 1 | <!DOCTYPE HTML> |
| 2 | <meta charset=utf-8> |
| 3 | <title>Layout Instability: observe timestamp after user input</title> |
| 4 | |
| 5 | <body> |
| 6 | <style> |
| 7 | #myDiv { |
| 8 | position: relative; |
| 9 | width: 300px; |
| 10 | height: 100px; |
| Xianzhu Wang | 48e5e3c | 2021-03-13 00:30:33 | [diff] [blame^] | 11 | background: blue; |
| Annie Sullivan | 99e2ef3 | 2020-08-11 14:45:42 | [diff] [blame] | 12 | } |
| 13 | |
| 14 | /* Disable the button's focus ring, which otherwise expands its visual rect by |
| 15 | * 1px on all sides, triggering a layout shift event. |
| 16 | */ |
| 17 | #button { |
| 18 | outline: none; |
| 19 | } |
| 20 | </style> |
| 21 | <div id='myDiv'></div> |
| 22 | <button id='button'>Generate a 'click' event</button> |
| 23 | <script src=/resources/testharness.js></script> |
| 24 | <script src=/resources/testharnessreport.js></script> |
| 25 | <script src=/resources/testdriver.js></script> |
| 26 | <script src=/resources/testdriver-vendor.js></script> |
| 27 | <script src=resources/util.js></script> |
| 28 | <script src=/event-timing/resources/event-timing-test-utils.js></script> |
| 29 | <script> |
| 30 | let timeAfterClick; |
| 31 | |
| 32 | promise_test(async t => { |
| 33 | assert_implements(window.LayoutShift, 'Layout Instability is not supported.'); |
| 34 | // Wait for the initial render to complete. |
| 35 | await waitForAnimationFrames(2); |
| 36 | |
| 37 | const startTime = performance.now(); |
| 38 | return new Promise(resolve => { |
| 39 | const observer = new PerformanceObserver( |
| 40 | t.step_func(entryList => { |
| 41 | const endTime = performance.now(); |
| 42 | assert_equals(entryList.getEntries().length, 1); |
| 43 | const entry = entryList.getEntries()[0]; |
| 44 | assert_equals(entry.entryType, "layout-shift"); |
| 45 | assert_equals(entry.name, ""); |
| 46 | assert_greater_than_equal(entry.startTime, startTime); |
| 47 | assert_less_than_equal(entry.startTime, endTime); |
| 48 | assert_equals(entry.duration, 0.0); |
| 49 | // The layout shift value should be: |
| 50 | // 300 * (100 + 60) * (60 / maxDimension) / viewport size. |
| 51 | assert_equals(entry.value, computeExpectedScore(300 * (100 + 60), 60)); |
| 52 | // We should see that there was a click input entry. |
| 53 | assert_equals(entry.hadRecentInput, false); |
| 54 | assert_greater_than_equal(timeAfterClick, entry.lastInputTime); |
| 55 | resolve(); |
| 56 | }) |
| 57 | ); |
| 58 | observer.observe({ entryTypes: ['layout-shift'] }); |
| 59 | // User input event |
| 60 | clickAndBlockMain('button').then(() => { |
| 61 | // 500ms delay |
| 62 | step_timeout(function() { |
| 63 | timeAfterClick = performance.now(); |
| 64 | // Modify the position of the div. |
| 65 | document.getElementById('myDiv').style = "top: 60px"; |
| 66 | }, 500); |
| 67 | }); |
| 68 | }); |
| 69 | }, 'Layout shift right after user input is observable via PerformanceObserver.'); |
| 70 | </script> |
| 71 | |
| 72 | </body> |
